Centerless grinder



May 7, 1940. S 2,199,457

CENTERLES S GR INDER Filed Oct. 22, 1938 3 Sheets-Sheet 1 Iz'a .5

INVENT OR.

ATTORNEY.

F. S. HAAS 3 Sheets-Sheet 2 CENTERLES S GR I NDER May 7, 1940.

Filed Oct. 22, 1958 INVEN l lm lllllll Q BY ATTORNEY.

y 7, 1 F. $.HAAS 2,199,457

CENTERLESSGRINDER Filed Oct. 22, 1958' s Sheet s-Sheet s zdzaj INVENTOR. KPfpM/cA J/ZQfls ATTORNEY.

Patented May 7, 1940 UNITED STATES PATENT OFFICE cnN'rEaLEss GRINDER.-

Frederick S. Haas, Cincinnati, Ohio, assignorto Cincinnati Grinders Incorporated, Cincinnati,

Ohio, a corporation of Ohio Application October 22, 1938, Serial No. 236,531

6 Claims.

A further object of this invention is to correv late the controls of a centerless grinder whereby a single lever can be utilized to govern both the wheel feed and the ejection of the work.

l5 Other objects andadvantages of the presentinvention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood 20 that any modifications may be madein the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

25 Referring to the drawings in which like reference numerals indicate like or similar parts:

Figure l is an elevational view partly in section of a centerless grinding machine. Figure 2 is an enlarged section on the line 2-2 30 of Figure 1.

Figure 3 is a cross section on the line 3-3 of Figure 2.

Figure 4 is an enlarged section taken on the line 4-4 of Figure 1. 35 Figure 5 is a diagrammatic view of the electrical control circuit.

Figure 6 is a detailed view of the infeed-control cam. Referring to Figure 1 of the drawings, the reference numeral Ill indicates the bed of a centerless grinding machine upon which is supported a regulating wheel I I and a grinding wheel I 2.

These wheels are' supported for rotation on opposite sides of an intermediate work support, in-

; dicated generally by the reference numeral l3.

'As is the usual practice in centerless grinding machines, the regulating wheel II is rotated at a relatively low speed to effect rotation of the work, while the grinding wheel I 2 is rotated at in a relatively high rate of speed to effect the actual grinding or stock removal.

In the present machine the support H for the grinding wheel I2, and for the motor l5 which drives the same, is pivotally mounted at IS on 6 the bed ill for oscillatory movement toward and from the work support. A cam follower roller I1 is rotatably mounted in the end of a stud I 8 depending from the free end of the support H. The roller l1 engages the periphery of an infeed control cam i9 secured to the end of a ro- 5 tatable shaft 20. Theshaft 20 extends the full length of the bed and is anti-frictionally supported at both ends for rotation relative thereto. The contour of the cam is shown in Figure 6,

and consists of a rapid traverse portion l9 and a 10 feed portion 20'. Rotation of the cam in a clockwise direction will move the grinding wheel to-- ward the work support, and rotation in a. mum tar-clockwise direction will cause the grinding wheel to move away from the work support.

Referring to Figure 4, a work rest blade 2| is mounted on the w'o'rksupport l3 for holding a work piece, such as 22, in parallel relation to the opposing faces of the grinding wheels. It will be noted that the work piece has anenlarged head 23 which prevents the work piece, from being'fed through between the grinding wheels, vand-it is, therefore, necessary in grinding work of this nature to insert the work in the grindingthroat between the wheels and withdraw the same after 25 grinding. from the same side of the wheels. Al-

though the work may be easily placed in position as by pushing it into the grinding throat it is much more diflicult to withdraw the work manually due to the small area available for grasping it, and furthermore, considerable time is lost if the work has to be unloaded manually. There has, therefore, been provided an automatic ejector comprising an ejection pin 24 which is mounted in an axially slidable bushing 25.

In order that the bushing may have a fixed range of movement, and stillprovide for the variations in the length of work being ground, means are provided for'adjusting the pin relative to the bushing. This means includes an adjustable stop 40 screw 26 which is threaded in the end of the bushing for engaging the end of the pin and determining the amount that it shall project beyond the end of the bushing. A lock nut 21 serves to clamp the screw in any determined position. The other end of the bushing is split to form a sortof chuck, and a clamping nut 28 is threaded on the split end for tightening the grip of the bushing on the pin.

The bushing has a block 29 secured midway of so its length to form a -connecting means with a shifter lever 30. The lever hasa forked end 3i v which embraces a pin 32 extending crosswise, of a recess 38 formed in the block. The lever is pivotally mounted on thesupport l3 at 3|. The

2 amassv bushing and lever are normally held in a retracted position by a spring 35 interposed between a shoulder 36 on the bushing and a shoulder it formed on the support. An adlustableset g screw 39 carried by the lever 30 determines the return position of the ejector pin. The lever to is actuated by a plunger w connected to the armature' 4 i of'an electric solenoid 42. The plunger 40 is normally held out of contact with the lever 30 by a long spring 43 which surrounds the plunger between a fixed shoulder 44 and a shoulder 45 on the armature 4|. It should now be apparent that when the solenoid is energized that the plunger 40 will move toward the right in Figure 4, rotating the lever to in a counterclockwise direction, thereby advancing the ejector pin 24 toward the work piece 22. It islnot intended that the ejector pin should follow the work through the throat, but more togive it a sharp go blow whereby the inertia of the work piece itself will complete the ejecting movement. By means of this mechanism, the operator may hold, a

work piece in position, ready 'to be inserted as soon as the finished work piece is automatically ejected, thus saving considerable time. As shown in Figure 5, electrical operation of the solenoid 42 is controlled by a switch member 48, which,

upon movement in one direction, will interconnect contacts 41 and 48, thus completing a cirg cult from a power main 48 through line W to solenoid 42 and return line II to a second power main 52.

Referring to Figures 1 and 3, the shaft 20 is rotated by a manually operable lever 63 con- 85 nected thereto, and since one hand of the operator is utilized for operating the lever 53, while the other hand is utilized for loading the work, means are provided whereby the control of the ejector is correlated with the movement-of the grinding wheel so that as the grinding wheel approaches its return position after a grinding operation, the elector will function automatically to elect the finished work piece. This is accomplished by the mechanism shown in Figures 2 and 3.- As 5 shown in Figure 2, use is made of a commercial snap switch such as the "Bees" having a switch member 66 operated by a pivoted lever 54 which has a roller 55 mounted in the end thereof. A

. hook-shaped actuating lever 56 is pivotally supm ported on a pin 51, and this lever partially surrounds the shaft 20 and rests on the roller 55'.

This lever carries a latch pawl 58 which is pivotah ly supported on the pin 5!. The pawl 68 has a bifurcated end to form a face 60 which is normal- 5 ly held in engagement with a pin Si by a spring pressed plunger 62. The spring 83 which actuates the plunger 62 is only alight spring.

The shaft 20,'as shown in Figure 3, has keyed thereto a sleeve its with arrintegral lug 64 in which is inserted a pin 85 forming a connection to spring 86. The other end of the spring is connected to a pin I? carried by the bed.- The spring serves to return the shaft and thereby the infeed control cam to a starting position. .This

5 position is shown in Figure 2. Integral with the sleeve 20a is a lug 6B which has a beveled back 09 for engaging the beveled face Ill of the latch pawl 68, whereby upon rotation in a counterclockwise directipn the lug will rotate the pawl 58 in a clockwise direction, overcoming the resistance of the spring 63 and eventually passing by the end of the pawl. During this rotation the grinding wheel isbeing fed into the work to effect the grinding operation. '5 Upon return movement of the shaft in a clockwise direction the lug Cl will engage the, face ll of-the pawl l6 and through the pin 6! will rotate the lever It in a coimtercl direction and thus depress the switchlever 54 which will close the switch and cause automatic ejection of the work. This movement of the shaft will continue a sumcient distance for the lug 88 to pass out of engagement with the face ll whereby the spring in the switch housing will return the lever 54 to its normal position, taking the lever 56 with w it, so that the parts will return to the position shown in Figure 2.

It will now be evident that an improved control means has been provided for a centerless grinder whereby a single lever may be utilized for feeding u the grinding wheel and controlling automatic ejection of the work as theigrinding wheel completes its return movement.

1. In a grinding machine having a work rest blade for supporting a work piece,.a grinding wheel movable toward and from said blade on one side thereof, means omthe other side of said 'blade for resisting the thrust of the grindin wheel on the work piece, the combination of a $6 manually operable control lever, motion transmitting connections from said lever for causing opposite directions of movement of the grinding wheel for opposite directions of movement of the lever, a power operated work ejector associated .10

therefor operable by the lever. whereby a unidirectional actuation of the levereflects projection and retraction of the elector. r

2. In a centerless grinding machine having opposed gr'inding wheels and a work rest blade forming a grinding throat. the combination of a cam for moving said grinding wheel toward and from the grinding throat, an ejector for removing a finished work piecefrom. said grinding throat, an electrical solenoid for actuating said elector, a rotatable shaft for actuating said cam, g and an electrical circuit for said solenoid includ- I 'ing a control switch and operable by said shaft during one direction of rotation thereof for successively closing and-releasing said switch. whereby the ejector is projected and withdrawn go during uni-directional movement of the lever.

3. In a centerless grinding machine having opposed regulating and grinding wheels and an interposed work support, the combination of a pivoted support'for the grinding wheel, a cam u rotatable in opposite directions for eflecting opposite directions of movement of the grinding wheel with respect to the. work support. a work ejector pin supported for movement parallel tothe face of said wheels, a solenoid for operating said elector, a control switch, a pivoted lever for operating said switch including a latching'pawl, a rotatable shaft for actuating'said cam, and means on said shaft for engaging said pawl during rotatlonin one direction to close said switch and, 5 thereby eilect election ofthe'work.

' 4. In a grinding machine havinga wheel mounted. for movement in a direction toward and from the work piece tome-operated upon, means for controlling said movement of the wheel, and 79 means for electing a completed work piece. the combination with said electorrof means for controlling the operation thereof including a power device, an actuator therefor, an operating lever for the actuator having a latch device pivoted thereto for movement in one direction therewith and in the opposite direction with respect thereto, and a rotatable member coupled with the feeding mechanism having a portion movable in an arcuate path intersecting the latch member whereby said portion will temporarily engage the latch member to transmit movement therethrough to the lever in one direction of actuation oi the projection and during continued uni-directional movement in its arcuate path will disengage the latch member to release the lever substantially as and for the purpose described.

5. In a grinding machine including work supporting means, a grinding wheel, and means for eilecting relative approach and retraction oi the grinding wheel and work supporting means, the combination with a projectible ejector disposed adjacent the work supporting means for effecting removal of a finished work piece, of a rotatably adjustable member for eflecting the relative approach and retraction of the work supporting andgrinding means, and means for effecting actuation of the ejector in timed relation to the rotation of said member, including anarcuate lever disposed in semi-circumscribing relation to the rotary member, means pivotally supporting the lever-at one end thereof, an ejector control device engaging the free end of the lever, an actuator carried by the rotary member and projecting therefrom, and an actuating latch pivoted to the lever for movement therewith and with respect thereto, said latch having a portion projectible into the path of movement of the projection on the rotatable member for actuation thereby whereby an amplified movement is im-' 3 parted to the free end of the lever, substantially as and for the purpose described.

6. In a grinding machine including work sup porting means, a grinding wheel, and means for efl'ecting relative approach and retraction of the grinding wheel and work supporting means, the combination with a projectible ejector disposed adjacent the work supporting means for effecting removal of a finished work piece, of a rotatably adjustable member for effecting the relative approach and retraction of the work supporting and grinding means, and means for effecting actuation of the ejector in timed relation to the rotation 01' said member, including an arcuate lever disposed in semi-circumscribing relation to the rotary member, means pivotally supporting the lever at one end thereof, an ejector control device engaging the free end oi the lever, an actuator carried by the rotary member and projecting therefrom, an actuating latch pivoted to the lever for movement therewith and with respect thereto, said latch having a portion projectible into the path of movement of the projection on the rotatable member for actuation thereby whereby an amplified movement is imparted to the free end 01' the lever, means foryieldingly forcing the latch member into the path of movement of the projection and means on the lever for limiting the extent of said movement whereby the latch and lever will move as a unit under influence of the projection in one direction 01' shifting of the rotatable member, but the latch will yield with respect to the lever upon reverse rotation of the member. I a

' FREDERICK S. HAAS. 

